Capacitance type material level indicator

[Detailed Description of the Invention]

[Industrial Application] The present invention relates to a system for the level of the material in an accumulation container etc. to be shown, and relates to the system by which the form which shows especially the level of material as a function of the electric capacity of material was improved. [Description of the Prior Art] About the level measuring device which measures a material level according to change of the electric capacity in a container using an electric capacity type probe, it is publicly known to JP,48-25562,A etc., for example. However, depending on this material level measuring device, electric capacity changes with hardware requirements, measurement of an exact material level is difficult, and it is Oh. In spite of the changing electric capacity by a hardware requirement, the trial which measures an exact material level is performed, for example, it is in application for utility model registration Showa 50-59635 (JP,51-139657,U), The standard electric capacity always immersed into a fluid under test and the detection electric capacity from which an immersion rate changes according to change of a surface, and electric capacity changes are measured, and the surface detecting device which measures a material level by a resonant circuit is indicated. However, the standard electric capacity is fixed, in order to correspond to the electric capacity which changes with hardware requirements remarkably, it is insufficient, and it conformed to the hardware requirement more, and the trial which detects a more exact material level was performed. As mentioned above, in various operation environment, the material level detector using an electric capacity probe is used, and operational characteristic changes remarkably according to the operation environment. That is, the electric capacity detected is subject to the influence of conductive etc. of the material covered by the electric capacity probe and the material itself from which a level is detected, especially the conductivity of the material itself tends to receive the influence by change of the operation environment. Therefore, as for this proofreading mode, moreover, if it is possible to carry out second proof positive [ of the standard electric capacity ] according to change of this operation environment, detection of a more exact material level is possible and it is preferred to be carried out automatically. [Problem(s) to be Solved by the Invention] Therefore, the subject of the present invention has a cheap manufacturing cost, and is to provide the system for displaying material levels, such as a Consummate container which can operate, also for high-reliability over an intermediary and a long period of time under various operation environment. The subject of the present invention is for Then to also provide simply the material level indication system of the type which can be proofread by a person unfamiliar to various application environmental conditions at the spot. At the spot, it is in providing the type material level indication system in which a second proof positive is possible quickly and automatically also by an operator unskilled in relation to this. The another object of the present invention is to provide the charge level indication system of an electric capacity section bar which is not influenced by the influence of the influence of the material covered on an electric capacity probe and/or the conductivity of the material detected, or a change conductive [ the ]. [Means for solving problem] According to [ in order to solve the above-mentioned subject ] the present invention, it is as a function of the material level in a container, As the function of the electric capacity of the oscillator means and; probe which are connected with the resonant circuit containing the electric capacity probe formed in the above-mentioned container so that change of electric capacity may be followed, and the above-mentioned resonant circuit containing the; above-mentioned electric capacity probe The calibration means for identifying the standard electric capacity which shows the predetermined material level in the phase detecting means and the; above-mentioned container following change of the phase angle in the above-mentioned oscillator means; the above-mentioned phase detecting means and the above-mentioned calibration means are followed further, As the function of the difference between the electric capacity of the above-mentioned probe, and the above-mentioned standard electric capacity, The 1st input from the phase detecting means on the system for displaying the level of the material in a container which comprises the means for displaying the material level in the above-mentioned container, and following the; above-mentioned phase detecting means in the :above-mentioned calibration means, The comparison means provided with the 2nd input from a reference means, and the output further following the 1st [ above-mentioned ] and the comparison value between the 2nd input; it is connected to the 2nd above-mentioned input, The reference means which shows the above-mentioned standard electric capacity; it is connected to a means for the output of the; above-mentioned comparison means to change the above-mentioned operating characteristic further including the means for changing the operating characteristic of the above-mentioned resonant circuit or the above-mentioned reference means. The charge level indication machine of an electric capacity section bar acquiring the predetermined comparison value during the above-mentioned 1st and 2nd inputs is provided. That is, the present invention means a system for the level of the material in a container to be shown as a function of the electric capacity of the material, The resonant circuit containing the electric capacity probe formed in the container so that change of electric capacity might be followed as a function of the level of the material in the container, An oscillator with the output connected with the resonant circuit containing the electric capacity probe, The phase detector following change of a phase angle [ in / as a function of probe electric capacity / the oscillator output ], The proofreading circuit for identifying the standard electric capacity which shows the predetermined material level in the container, From the output circuit for following the phase detector and a proofreading circuit, and displaying the material level within the container as a function of the difference between the electric capacity of the probe, and standard electric capacity to and Be formed The identification circuit contains the comparison machine provided with the 1st input following a phase detector, and the 2nd input that shows standard electric capacity. It is possible to change the operating characteristic of a system during what is called proofreading operation, and it can acquire a predetermined comparison value resonance of a resonant circuit in general preferably with a comparison machine. Preferably, the above-mentioned identification circuit operates automatically when starting proofreading operation, can change the operating characteristic of a system like the resonance characteristic of the resonant circuit of a standard input over a comparison machine, thus can obtain the operation the request was beforehand decided to be about resonance. [Example] Below, the example of the present invention is explained in full detail, while referring to an accompanying drawing. Drawing 1 shows the suitable example of a material level indication machine based on the present invention. From the 1st output of RF oscillator 10, a periodic signal is sent to Transfer phase (90 *) amplifier 12. The sine wave output from amplifier 12 is connected to parallel LC resonant circuit 14 which can be adjusted. Resonant circuit 14 is connected to probe conductor 18 of probe assembly 20 (Drawing 1st [ the ] and 6) attached to the side wall of accumulation container 22. The output of amplifier 12 lets unit gain amplifier 24 which has low output impedance again pass, and is connected to protective shield 26 of probe assembly 20. They are a solid material accumulation container or a fluid accumulation tank. The wall of container 22 is grounded. As everyone knows, the electric capacity between probe conductor 18 and the wall in which container 22 was grounded is changed with the level of material 28 accumulated into a container, and the dielectric constant of the material. Change of this electric capacity is detected by other electronic circuits of the device concerned, and the display of the request about a material level is obtained. Although protective shield 26 is excited in general by Equipotential and the equi-phase with probe conductor 18 and amplifier 24, Since the energy leak through the material covered on the probe surface of a probe is prevented by this protective shield 26 and the energy radiation from a probe is limited in a container with it, the closer corresponding movement to the accumulated material level is obtained. The sine wave output of amplifier 12 lets zero intersection detector 30 pass, and is sent to one input of phase detector 32. Phase detector 32 receives the 2nd input that is a rectangular wave from the 2nd output of oscillator 10. In the 1st output of the oscillator in which this rectangular wave was sent to amplifier 12, a 180 * phase is Be tangled up. The 1st output of phase detector 32 is a direct current signal of a level proportional to phase relation during each input. This 1st output is supplied to automatic proofreading circuit 34. The 2nd output of phase detector 32 is also a direct current signal which shows input phase relation, and this 2nd output is sent to one input of Thread thread detector 36. Thus, although the output of phase detector 32 is the same, since it is a reason mentioned below, it dissociates to mutual effectively. Automatic proofreading circuit 34 sends a control input to LC resonant circuit 14 which can be adjusted, and resonant circuit 14 receives the 2nd input for adjustment from oscillator 10. Automatic proofreading circuit 34 sends a standard input to Thread thread detector 36 on the other hand. The output of Thread thread detector 36 lets material level indication circuit 38 pass, and is sent to the external circuit for controlling and/or displaying the material level in a container according to a request. Generally a Fitted electric capacity level is detected by the predetermined material conditions which automatic proofreading circuit 34 functions as adjusting the resonance characteristic of resonant circuit 14 in the case of the proofreading mode started by connected push button 40 for operators, does in this way, and exist in container 22 between automatic proofreading modes. Preferably, even the level of a probe assembly is first filled up with the material in container 22 (means which is not illustrated), it descends so that material may be isolated from the level of a probe assembly after that, and change of the electric capacity level is detected. On the other hand, in arrangement of the type that material 28 usually covers a probe assembly, since material is [ the Be covering up state ] usually a state, a probe top is taken into consideration when this is proofreading operation. When a material level descends, an operator pushes button 40 and makes automatic proofreading mode start. The resonance characteristic of circuit 14 is automatically changed by proofreading circuit 34, and is adjusted again until the output of phase detector 32 shows that the parallel combination of resonant circuit 14 and electric capacity probe 18 has the phase relation beforehand selected to the oscillator standard input to phase detector 32. This phase relation is equivalent to the standard electric capacity level used in order to show that a material level is low in automatic proofreading circuit 34. Then, the output of phase detector 32 is measured with the standard input from proofreading circuit 34 which shows the standard electric capacity level in Thread thread detector 36 among normal operational mode. Thread thread detector 34 sends an output to material level indication circuit 38, when the electric capacity of the detected material exceeds a standard electric capacity level only in the specified quantity. In the specified quantity [ above-mentioned ], it is beforehand set up as a function of the dielectric constant of material. As shown in Drawing 1, when probe 20 is laid in the upper part of container 22, approaching a probe will show the full state of a tank. On the other hand, when probe 20 is arranged at the lower part of a tank, material is usually that of Be covering up in proximity, i.e., a probe, at probe 20, and the case where this state changes will show the nil state of a tank. Drawing 2 has illustrated the desirable example of automatic proofreading circuit 34 and LC resonant circuit 14 which can be adjusted. As for these, the output of amplifier 12 is connected in parallel with probe conductor 18 between a horizontal OFF intermediary's, i.e., amplifier 12, output, and grounding including capacitor 42 and inductance 44 to which resonant circuit 14 was fixed. Inductance 44 equips with many connection A tap the position where the inductor coil is located separately electrically between inductor coil winding including a plurality of inductor coils, i.e., winding. It is electrically connected to electronic switch 48a~48f respectively controlled separately between corresponding connection A tap and electric grounding on inductance 44 in series a plurality of fixed capacitor 46a~46f. In the state where there is no control input, it has usually opened wide including a certain suitable electronic switch switch 48a~48f. digital counter 50 -- the calculation from oscillator 10 -- an input is received and a plurality of parallel digital outputs which show A bit to which the calculation by which each is stored in counter 50 corresponds are outputted. Each data bit output of counter 50 is connected to corresponding electronic switch 48a~46f, and the alternative connection or separation of capacitor 46a~46f to which resonant circuit 14 corresponds is performed as a function of an output A bit state of a counter. The number of coil winding which has separated connection A tap of a capacitor 46a~46f electric capacity value and inductance 44 according to the feature of the suitable example of the present invention shown in Drawing 2, The effective electric capacity applied to parallel LC resonant circuit 14 by each capacitor 46a~46f is chosen so that it may correspond to the dignity of the numerical value of the corresponding counter output. Namely, when it is 2 Advance counter in which counter 50 has temporarily the output connected to switch 48a~48f in a reverse order of numerical dignity, A capacitors [ 46e and 46f ] value and the number of winding in inductance 44 in the meantime, It is chosen so that it may become twice, when only switch 48e is closed as compared with the time of only switch 48f being closed for the effective electric capacity connected in parallel with fixed capacitor 42 and probe 20. Similarly, the effective electric capacity applied by switch 48a and capacitor 46a is 32 times the effective value of capacitor 46f and switch 48f. Inductance 44 is functioning as establishing the effective electric capacity of each capacitor 46 as a corresponding function of a connecting point between the inductance coil as a single volume transformer so that the upper statement may show. When 2 or the capacitor beyond it is connected to one A tap, the number of capacitor connection A tap becomes less than a capacitor 46a~46f number. The value of the capacitor connected to common A tap is [ multiple of 2 ] different in general corresponding to the dignity of control A bit from counter 50. Including one shot circuit 52, this one shot circuit 52 receives the input from operator push button 40, and automatic proofreading circuit 34 illustrated in Drawing 2 sends an output to the reset input of counter 50 in resonant circuit 14, and starts automatic proofreading mode. Differential comparison machine 54 has a reversed input connected to the wiper of the reversal input and variable resister 56 which are connected to the output of phase detector 32. Horizontal OFF intermediary connection of the resistor 56 is made in the direct-current potential source. The output of comparison machine 54 is connected to the possible-ized input of counter 50 of resonant circuit 14. The output of comparison machine 54 lets resistor 57 pass again, it is connected to the base of NPN transistor 58 which functions as an electronic switch, and, as for the emitter and collector of transistor 58, the direct-current potential source is connected with horizontal OFF intermediary LED60, resistor 61, and the operator's push button 40 in series. The reversed input of comparison machine 544 is connected also to Thread thread detector 36 (Drawing 1st [ the ] and 3) through resistor 62 which can be adjusted. If push button 40 is pushed by the operator, counter 50 will be cleared namely, reset and automatic proofreading operation will begin. Capacitor 46 is altogether separated from resonant circuit 14. For the material covered on a probe, the resonance by the side of "inductance" is removed in general, and the output from phase detector 32 to comparison machine 54 becomes high. Therefore, since differential comparison machine 54 supplies a low output to the possible-ized input of counter 50, and the base of transistor 58, bias of the transistor 58 is carried out to non-switch-on, and LED60 is made into a non-excitation state. the calculation pulse-ized from oscillator 10 when counter 50 was reset and made possible -- an input advances calculation of counter 50 and there are several kinds [ an input ] thereby -- capacitor 46a~46f -- switch 48a~48f -- control -- therefore, a parallel LC resonant circuit -- continuation -- and it connects alternatively. The effective electric capacity obtained by connection of each capacitor is proportional directly in relation to the dignity of the numerical value of A bit to which counter 50 corresponds as above-mentioned. The output of phase detector 32 decreases towards a standard level as capacitor 46 is connected in parallel with inductance 44, capacitor 42, and probe 20 and this parallel combination approaches resonance of the frequency of oscillator 10. This standard level is determined by setup of variable resister 56 by the side of the reversed input of differential comparison machine 54. As for resistor 56, it is preferred that there is no covering in probe 20 and the state where all the capacitor 46a~46f is the nominal capacitance of the low level connected to the circuit, i.e., an "empty container", and circuit 16 resonates Set at a factory. The electric capacity of the empty tank in probe 20 is 15 pF, for example. If the output of phase detector 32 reaches the input which shows the level of the standard electric capacity to comparison machine 54 (i.e., if the resonance state of LC resonant circuit is reached in general), the output of differential amplifier 54 will switch to a high state, i.e., the state of logic 1. Counter 50 stops future operations and it is displayed on an operator that LED60 illuminated and proofreading operation was completed. According to this, an operator opens switch 40. Thus, all the capacitor 46a~46f is connected into a circuit, and a resonant circuit is in the state where a probe is not covered, and is set up to be in the resonance state. Automatic proofreading operation functions as removing Sandesa 46a~46f beyond one or it from a parallel resonant circuit, in order to compensate change of the operating characteristic of covering on a probe, the electric capacity of a cable, the Geometry structure of a tank, parasitism electric capacity, probe insertion length, and a circuit. Electric power is supplied to all above-mentioned circuits (and described below) from the suitable power supply excited by commercial power. Preferably, further, even if the Bathroom is connected to the power supply input terminal of counter 50 via prevention diodes 66 and 68 in parallel with a direct-current power supply including battery 64 and it faces [ failure of a power supply ] LC resonant circuit 14 which can be adjusted, it can maintain calculation of the proofreading. Now, Thread thread detector 36 is for referring to Drawing 3, This operation comparison machine 70 has the reversal input connected to the 2nd input of phase detector 32 (Drawing 1), and a reversed input connected to resistor 56 in which standard-display adjustment is possible through resistor 62 (Drawing 2) which can be adjusted including operation comparison machine 70. Between the reversal input of comparison machine 70, and grounding, it is connected through jumpers 76 and 78 in which one pair of capacitors 72 and 74 correspond. The 3rd capacitor 75 is connected between the reversal input of comparison machine 70, and grounding. Capacitors 72, 74, and 75 and jumpers 76 and 78 give selectable delay to operation of Thread thread detector 36 at a factory or the spot so that the incorrect Ivy display of a material level may not be made by an excessive state. Since the output of the phase detector is isolated mutually as mentioned above, capacitors 72, 74, and 75 for delay do not influence the operation in proofreading mode. Between the reversed input of comparison machine 70, and grounding, one pair of resistors 80 and 82 are connected via jumpers 84 and 86 of correspondence. The 3rd resistor 87 is directly connected between a reversed comparison machine input and grounding. Resistor 62 (Drawing 2) is adjusted [ resistors 80, 82, and 87, jumpers 84 and 86, and ] further suitably at a factory or the spot, The electric capacity difference detected by Thread thread detector 36 can be adjusted between the standard set up by resistor 56 (Drawing 2), and the material-approximation material level which probe 20 tends to display. When probe assembly 20 is shown in Drawing 1, The difference between the electric capacity level of probe 20 which is equivalent to the standard level of resistor 56 in case material is on a low level since it is laid in the upper part of container 22, and electric capacity when a tank is full, A material level is equivalent to an increased part of the electric capacity resulting from having approached the electric capacity probe and having gone up. Between low A week quantity material level states, a detection To be electric capacity difference is effectively chosen with resistors 80, 82, and 87 and jumpers 80 and 84. To the material of a low dielectric constant like cement, the Thread thread level which jumpers 84 and 86 are opened wide, for example, is equivalent to a 4-pF electric capacity difference is set up by resistors 62 and 87. To the material of a middle dielectric constant like acetone, jumper 84 is added and an 8-pF higher electric capacity difference is set up, for example to the same material level height as the above by resistors 80 and 87 arranged in parallel. A high electric capacity difference opens jumper 84 wide, and is set up by adding jumper 86. Since the both sides of jumpers 84 and 86 are connected to the material of a comparatively high dielectric constant like glycerin, resistors 80, 82, and 87 arranged in parallel are set, for example as the 20-pF greatest electric capacity difference. From a resonating point of the tank near empty in general that the output from phase detector 32 was set up by the above-mentioned automatic proofreading mode, When decreasing to the level set up by resistors 56, 62, 80, and 82 and/or 87, the output of differential comparison machine 70 switches from a low level, i.e., logic 0, to a high level, i.e., logic 1, and it indicates that material approached the probe assembly by that cause. Resistor 88 is connected between the output and the reversed input of comparison machine 70, operation of a comparison machine is made to produce a hysteresis, and, thereby, it is avoided in the state of the material level near a boundary line that a comparison machine output switches intermittently. The output of differential comparison machine 70 is connected to one input of exclusive OR gate 90 of material level indication circuit 38. The 2nd input of gate 90 is further connected with the positive source of voltage through resistor 94 at grounding through jumper 92. The output of gate 90 magnetizes relay coil 100 at the same time it lets resistor 95 pass, and is connected to the base of NPN transistor 96 which functions as an electronic switch and the output of gate 90 illuminates LED98 through resistor 99 to a I got it. case for a high level, i.e., logic 1. As above-mentioned, it is connected to the terminal in which terminal block 104 corresponds, and point of contact 102 interlocked with relay coil 100 is connected to an external circuit. Jumper 92 and resistor 94 collaborate with gate 90, and choose either the low level failsafe operation of material level indication circuit 38, or high level failsafe operation. That is, jumper 92 and resistor 94 collaborate with gate 90, and make relay coil 100 no magnetizing in either the state (material is close to probe 20) of a high level, or the state (material is being isolated from probe 20) of a low level. Thus, that state of a high level where it was chosen, or the state of a low level is independently displayed on that external circuit device as an actual material level, also when relay coil 100 is-less magnetized by failure of a power supply etc. As above-mentioned, the output of comparison machine 70 takes the state of a high level, i.e., logic 1, when material 28 is close to probe 20 (Drawing 1). When the failsafe operation of a low level is required (i.e., when being-less magnetized in order to show a material level with low relay 100), jumper 92 is opened wide and a low level, i.e., the voltage level of logic 0, is placed by the 2nd input of gate 90. In this composition, the output of gate 90 follows the 1st output from comparison machine 70, When LED98 is always illuminated when material is close to the electric capacity probe, relay coil 100 is magnetized and material is isolated from a probe (low level), LED and a relay coil are made no magnetizing. On the other hand, when the failsafe operation of a high level is required, jumper 92 is connected and a high level, i.e., the voltage level of logic 1, is placed by the 2nd input of gate 90. Therefore, the output of a gate is although LED98 is illuminated and relay coil 100 is magnetized, when it will become opposite to the 1st input from comparison machine 70 and a material level is in an isolation position from a probe (low level), When material is close to a probe (high level), both LED and a relay coil are placed by the state where it does not magnetize. Drawing 4th [ the ] and 5 shows another example of the circuit based on the present invention. Only difference with the above-mentioned example is illustrated in Drawing 4th [ the ] and 5, and the following description is also restricted to the range. The resonant circuit which cannot be adjusted is substituted for LC resonant circuit in the above-mentioned example which can be adjusted by correction of Drawing 4. the resonant circuit which cannot be adjusted [ this ] comprises fixed capacitor 104 and fixed inductance 102 -- these -- mutual -- and probe 20 stands in a row. As for capacitor 104 and inductance 102, it is preferred to be chosen so that it may resonate, when the electric capacity at the time of the about 15-pF empty tank of probe 20 (not covered with material) and oscillator 10 are put together, for example. The A bit parallel data output of counter 50 is sent to digital-to-analog conversion machine 106 instead of the fixed power source voltage in the above-mentioned example, and analog output voltage is supplied to standard resistor 56 with this digital-to-analog conversion machine. Differential comparison machine 54 receives the input from phase detector 32 and standard resistor 56, And equally to the output of phase detector 32 and others equivalent to a covering probe sky container proofreading state in probe 20, the reference voltage supplied to the reversal input of comparison machine 54 by resistor 56 removes the possible-ized input from counter 50 to a Noodle case, and terminates automatic proofreading mode to it. The calculation to which counter 50 corresponds is held, and after that, as above-mentioned, the output of D/A converter 106 is maintained at a fixed value so that empty tank reference voltage may be given to Thread thread detector 36. Thus, the standard level supplied to Thread thread detector 36 (Drawing 1st [ the ] and 3) by resistors 56 and 62 in the corrected proofreading circuit which is shown in Drawing 4 shows the both sides of the electric capacity of the probe of an empty tank, and an added component. This added component is not prevented with protective shield 26 based on the material covered on a probe, either. Drawing 5 shows changed resonant circuit 107 which can be adjusted. This resonant circuit 107 is controlled by the output of D/A converter 106, and in order to change that effective inductance as a function of calculation of counter 50, it contains direct-current current source 108 connected to coil 102. Current source 108 is provided with the emitter which this transistor 110 is connected to the output of amplifier 12 (Drawing 1) through capacitor 112 including PNP transistor 110, and is connected to the positive source of direct-current voltage through resistor 114. On the other hand, the base of transistor 110 is connected to the output of D/A converter 106 in the source of voltage through resistor 116. The collector of transistor 110 is connected to the parallel resonant circuit containing inductor 102, capacitor 104, and probe 20. the direct-current current which the calculation in counter 50 increases into automatic proofreading mode and which is alike, takes and is supplied to inductor 102 by transistor 110 corresponds and decreases -- thereby The effective exchange inductance of inductor 102 is decreased in order to compensate the increased probe electric capacity resulting from covering material. If the effective inductance decreases and capacitor 104, inductor 102, and the covered parallel combination of probe 20 reach a resonating point in general, operation of counter 50 will stop with differential comparison machine 54 (Drawing 2) like the above. Resistor 116 is variable and can adjust a current profit at a factory. closed-down type metal housing 120 for which Drawing 6 shows the suitable example of probe assembly 20 based on the present invention, and the probe assembly 20 has base 121, a base, and separable cover 123 -- with, it is shown. The above-mentioned electronic circuit is preferably provided in housing 120, and it is connected to an external circuit device via opening 122 of base 121, Electric power is received from the power supply arranged in the position isolated with the probe assembly, and the proofreading signal from switch 40 (Drawings 1 and 2) arranged in the position similarly isolated with the probe assembly is received, and also it is connected to terminal switch 104. Nipple 124 in the air has projected from base 121 of the housing. From the end of the one away from the housing of nipple 124, the female screw is turned off until it results in inboard at Toward or shoulder 125 which carries out an intermediary taper surface owner. In nipple 124, adapter 130 in the air by which the male screw is turned off is received. The inside of adapter 130 has the 1st diameter 128, and the 1st diameter 128 is following 2nd smaller diameter 129 via shoulder 131 which has a taper surface. Diameter 128,129 and shoulder 131 have a coaxial relation, when nipple 124 is assembled. The end of the one away from the housing of adapter 130 is proofread possible [ screwing to 140 ] even for the packing gland by which the female screw was turned off. As 140 is laid on the side wall of material accumulation container 142, or a top wall, thus even this packing gland is shown in Drawing 1, Rod 18 and protective shield 26 of a probe project inside a container. probe measuring element 18, protective shield 26, and its circumference -- and subassembly 133 of the probe which comprises integral-type main part 126 of the insulating material formed between them is caught in the shape of seal by nipple 124 and adapter 130. Measuring element 18 comprises solid Rod made from the conductive and corrosion-resistant charge of a metallic material like stainless steel, has the opening which had the female screw turned off at the end, and can connect it to resonant circuit 14 (Drawing 1) which can be adjusted in portion 134 in housing 120. Protective shield 26 encloses Rod 18 of a probe in the shape of the same axle, and comprises a hollow cylindrical tube made from the conductive charge of a metallic material like the stainless steel rope located separately from the Rod in a radial direction. Protective shield 26 in a suitable example is substantially shorter in an axis size than in Rod 18 of a probe, and is located separately in the middle of the Rod end. The protective shield is extended to the position located separately from the direction end away from the housing of Rod 18 of a probe from the position inside [ which is separated from the housing of adapter 130 / radial ] the end of a direction. Insulating conductor 132 is soldered to protective shield 26, or it is electrically connected, and the conductor 132 is prolonged into Along housing 120 in Rod 18 for connection with amplifier 24 (Drawing 1) separated from the Rod element. Insulating material 126 contains the 2nd portion that is surrounding externally the 1st portion that is surrounding Rod 18 of the probe inside protective shield 26, and protective shield 26. The end of the one away from the housing of Rod 18 of a probe was not covered with an insulating material, but is exposed. Insulating material 126 is [ in / surround an end located separately in the direction of an axis of protective shield 26, and / a radial direction ] Heavy intermediary ing. It exposes radially and the Intermediate position circumference is not covered with an insulating material. In particular, an insulating material is formed in one as A lip continuous in the circumference, and overlaps with the end and radial direction of a direction away from the housing of protective shield 26, and it can catch it in the shape of seal. Shoulder 136 continuously developed in the circumference radially is formed on insulating material 126, and has a taper surface to the direction of an axis. The taper surface is caught in the shape of seal in an assembly between shoulder 125 on nipple 124, and shoulder 131 on adapter 130. Circumference Notch 137 beforehand formed in Rod 18 is filled up with the radial inner side of shoulder 136 by the insulating material so that it may hold Rod on an axis. Main part 126 of the insulating material shown in the 6th is symmetrical around the probe axis. In manufacture of probe assembly 20, protective shield 26 (conductor 132 is attached) and Rod 18 of a probe are first fixed on the same axle within a suitable metallic mold (not shown). Then, insulating material 126 is formed in the circumference of the protective shield and a probe element, and the meantime as solid construction by single work of injection mall Dengue. The edge of the protective shield is bound tight so that A lip 139 of Heavy intermediary There may form a close pressure-resistant seal at the end away from the housing of protective shield 26 radially, as an insulating material gets cold and contracts. The length of Rod 18 of protective shield 26 and a probe is chosen according to an operating mode. As insulating material 126, a certain suitable heat resistance and a corrosion-resistant material are used. For example, the material of marketing [ Petroleum / Philips ] by the proprietary name "RYTON" Becoming is preferred. [Effect of the Invention] According to the above-mentioned example based on the present invention, as compared with the device same type, it has many important advantages. For example, also when it originates in the change for humidity etc. and the conductivity of material is rather changed from the amplitude of a probe signal by the corresponding movement nature of a material level detector circuit device to the phase angle, the level detector circuit device cannot be affected easily. In the example of all above, a second proof positive is easily possible at any times by holding as the operator only pushed switch 40 (Drawing 1st [ the ] and 2), and the switch is pushed until LED60 (Drawing 2) illuminated. directions of the factory which the display for indication was manufactured as the same thing at the factory, and was specified beforehand -- therefore, it is correctable in order to make specific application suit at the spot by removing one or jumpers 76, 78, 84, and 86 beyond it. Therefore, a contractor can lessen the kind of model which must be prepared beforehand and is economical. In addition to what was described in detail, many change and corrections are possible for the present invention till now so that clearly from the above explanation. Although the proofreading operation by the example of Drawing 2nd [ the ], 4th [ the ], and 5 is indicated to be what is performed automatically, Or [ that proofreading by manual operation may be sufficient and this manual proofreading gives the electric capacity and/or the Inductive tank which can be adjusted manually to the parallel resonant circuit in the large viewpoint of the present invention ], Or it is attained by giving hand regulation about standard resistor 56 in a method similar to the automatic adjustment arrangement of Drawing 4.

[Brief Description of the Drawings]

Drawing 1 is the present invention. it is a functional block diagram of the suitable example of the charge level indication machine of an electric capacity section bar to twist --; -- Drawing 2 shows the suitable example of the automatic proofreading circuit of the charge level indication machine of an electric capacity section bar by the present invention, and LC resonant circuit which can be adjusted --; -- Thread thread of the charge level indication machine of an electric capacity section bar according [ Drawing 3 ] to the present invention the suitable example of the circuit of a detector is shown --; -- Drawing 4 shows another example of LC resonant circuit of the charge level of an electric capacity section bar shown in Drawing 2 --; -- Drawing 5 shows another example of LC resonant circuit of the charge level of an electric capacity section bar shown in Drawing 2 --; -- further Drawing 6 shows the fracture To elevational view partially [ the electric capacity detection probe by the desirable example of the present invention ]. 10: RF Oscillator, 12: Amplifier, 14:LC Resonant Circuit, 18 : Probe Conductor, 20: Probe Assembly, 22: Accumulation Container, 26 : Protective Shield, 28: Material, 30: Zero Intersection Detector, 32: Phase Detector, 34 : Automatic Proofreading Circuit, 36: A Thread thread detector, 38: A material level-indication circuit, 40: A push button, 44: Inductance, 46: A capacitor, 48: A switch, 50: A counter, 52: A one shot, 54: A differential comparison machine, 56: A variable resister, 58: A transistor, 60:LED, 64 : battery.